An updated review on bluetongue virus: epidemiology, pathobiology, and advances in diagnosis and control with special reference to India

Abstract

Bluetongue (BT) is an economically important, non-contagious viral disease of domestic and wild ruminants. BT is caused by BT virus (BTV) and it belongs to the genus Orbivirus and family Reoviridae. BTV is transmitted by Culicoides midges and causes clinical disease in sheep, white-tailed deer, pronghorn antelope, bighorn sheep, and subclinical manifestation in cattle, goats and camelids. BT is a World Organization for Animal Health (OIE) listed multispecies disease and causes great socio-economic losses. To date, 28 serotypes of BTV have been reported worldwide and 23 serotypes have been reported from India. Transplacental transmission (TPT) and fetal abnormalities in ruminants had been reported with cell culture adopted live-attenuated vaccine strains of BTV. However, emergence of BTV-8 in Europe during 2006, confirmed TPT of wild-type/field strains of BTV. Diagnosis of BT is more important for control of disease and to ensure BTV-free trade of animals and their products. Reverse transcription polymerase chain reaction, agar gel immunodiffusion assay and competitive enzyme-linked immunosorbent assay are found to be sensitive and OIE recommended tests for diagnosis of BTV for international trade. Control measures include mass vaccination (most effective method), serological and entomological surveillance, forming restriction zones and sentinel programs. Major hindrances with control of BT in India are the presence of multiple BTV serotypes, high density of ruminant and vector populations. A pentavalent inactivated, adjuvanted vaccine is administered currently in India to control BT. Recombinant vaccines with DIVA strategies are urgently needed to combat this disease. This review is the first to summarise the seroprevalence of BTV in India for 40 years, economic impact and pathobiology.

Human cell receptors: potential drug targets to combat COVID-19

“…The binding affinity of SARS-CoV-2 for ACE2 is 10–20 times higher than of SARS-CoV (Wrapp et al 2020 ). Thus, SARS-CoV-2 is highly contagious and transmissible, though having a lower mortality rate (Petrosillo et al 2020 ) than SARS-CoV and MERS-CoV, which are chiefly responsible for the nosocomial spread (Malik et al 2020 ).…”

Sero-epidemiological survey of bluetongue disease in one-humped camel (Camelus dromedarius) in Kassala State, Eastern Sudan

“…Bluetongue (BT) is an infectious disease of ruminants caused by bluetongue virus (BTV) which belongs to the Orbivirus genus of the family Reoviridae with at least 28 recognized serotypes [ 1 ]. In sheep and certain species of deer, the clinical disease is most common [ 1 ] whereas cattle, goats and camelids usually have sub-clinical disease [ 2 – 4 ]. Bluetongue virus transmission from animal to animal requires insect vectors.…”

“…Bluetongue virus transmission from animal to animal requires insect vectors. Culicoides midges are the main vectors of the virus, with C. imicola being the main vector species in Africa and southern Europe [ 1 ]. At least, four BTV serotypes designated as serotypes 1, 2, 4 and 16 are enzootic in different states of Sudan [ 5 , 6 ].…”

“…These serotypes (1,4 and 16) were recovered from sentinel calf herds at Shambat (Khartoum) [ 5 ]. The sheep breeds, such as Sudanese ecotypes of sheep, may develop clinical disease while cattle and camelids mostly develop sub-clinical infections [ 1 ]. Similarly, the clinical reaction of camels to disease agents such as Foot and mouth disease (FMD), Rinderpest, Bovine viral diarrhea (BVD, Rift valley fever (RVF), Parainfluenza-3 (PI3) and Bovine herpes virus-1 (IBR) is usually not apparent nor is it expected, and illness may pass unnoticed [ 7 ].…”

Is Bluetongue Virus a Risk Factor for Reproductive Failure in Tropical Hair Sheep in Brazil?

“…The infection of pregnant ewes may lead to transplacental infection and it might result in early embryonic death, fetal mummification, abortion, stillbirth and birth of weak lambs. Moreover, it has also been described the birth of non-viable offspring with severe central nervous system deformities as porencephaly, hydrocephalus, hydranencephaly and brain cysts [1, 23,25,26].…”